Growth and field emission property of ZnO nanograsses

• Well-aligned ZnO nanograsses were grown on silicon substrate using thermal chemical vapor transport and condensation methods.
• The field emission properties of ZnO nanostructures were studied.
• ZnO nanograsses array showed excellent field emission property and can be a promising candidate for an emitter.
• The interesting mechanism explained the formation of ZnO nanograsses.

Well-aligned ZnO nanograsses are fabricated on silicon substrate using thermal chemical vapor transport and condensation (CVTC). The field emission property of ZnO nanograsses array is characterized. The low turn-on electronic field and the high current density are achieved with ZnO nanograsses array as the emitters. It is suggested that the special morphology of ZnO nanograsses play a crucial role for its excellent field emission property, and well aligned ZnO nanograsses can be a promising candidate for an emitter. The growth mechanism of ZnO nanograsses can be explained by the combination of vapor–solid (VS) and vapor–liquid–solid (VLS) processes. The higher ZnO concentration around the silicon substrate and metal catalyst seem to play crucial roles in the formation of ZnO nanograsses.